The rheological and sensoric benefits and organic compatibility of silicone compounds have contributed immensely to their usefulness in a wide variety of personal care compositions, including skin creams, lotions, antiperspirants and deodorants, color cosmetics (e.g. mascara, lipstick) suncare products and hair conditioners.
A variety of patents describe various types of formulations based on silicone compounds, like dimethiconol, polyalkylsiloxanes, polyalkylarylsiloxanes, polyestersiloxanes, polyethersiloxanes, polyfluorosiloxanes, polyaminosiloxanes and combinations thereof. Especially, the use of dimethylsilicones, both linear and cyclic, provide desirable sensory benefits during application. Non-volatile silicones provide desirable sensory attributes to the hair and to the skin subsequent to the application. Unfortunately, dimethylsilicones show limited compatibility with many organic materials used in cosmetic formulations. Also they are generally not compatible with water.
Phenyltrimethicones, of the general formula Me3SiO[Si(Me3SiO)(Ph)O)]xSiMe3, with x from 1 to 3, are a class of silicones which show excellent compatibility with many organic ingredients. Phenyltrimethicones are formulated into cosmetic products for a number of purposes including better gloss and sheen of hair, increased emolliency and water repellency of the skin. During the application of cosmetic products said phenyl trimethicones also provide enhanced spreadability and lubricity and reduced tackiness.
Considerable study has been carried out in recent years concerning the ultimate fate of organosilicones (atmosphere, rivers and lakes).
Phenyl substituents are oxidized and/or homolytically cleaved from silicon forming benzene and/or phenol. Both are considered to be pollutants of the environment.